| Nowadays,prefabricated structure has the advantages of design diversity,short construction period,low production cost and high building quality,so it has become the development trend of housing industrialization in China.As an important connector in prefabricated structure,grouting sleeve has the characteristics of low cost and good mechanical performance.At present,most of the grouting sleeves on the market are made of ductile iron,which has smooth interior,high production cost and general mechanical performance.The new ribbed grouting sleeve designed in this paper is cold rolled from seamless steel tube,which has the advantages of simple processing,low production cost and good mechanical performance.In this paper,the stress and seismic performance of grouting sleeve are studied and analyzed by combining test and simulation.The main research contents are as follows.In this paper,two sets of reinforced connection sleeves with diameters of 12 mm and16 mm are designed as the research objects.Each group has 15 sleeves,including ribbed and unribbed sleeves.The anchorage length of the connecting steel bar,the number of ribbed inside the sleeve and whether the steel bar is offset were taken as the research variables.The axial tensile test of the designed grouting sleeve was carried out,and the failure mode and mechanical performance of the sleeve were studied and analyzed.The sleeve with excellent test results was used as the connection specimen of the prefabricated beam-column joint model.The axial compression ratio of the joint is set as a variable,and the cast-in-place joint of the same size is set for comparative analysis.ABAQUS finite element software was used to study the seismic performance of the joints.(1)From the load-displacement curve of the test,it can be concluded that the sleeve with an anchorage length of 8d has a greater bonding force between the steel bar and the grouting material,and is stronger in bearing performance and mechanical performance.Comparing the load displacement curve of the test piece,it can be seen that the sleeve with 8 ribs,the bonding force between the sleeve and the grouting material increases,and the overall mechanical performance of the test piece increases;compared with the load displacement curve,when the steel bar was aligned,the contact surface between the steel bar and the grouting material is larger than that of the steel bar offset,and the bonding force between them is stronger,so the bearing capacity is larger and the mechanical performance is better.(2)When the axial compression ratio of the joint increases,the total area of the hysteresis curve of the two specimens decreases.In the skeleton curve,the ultimate bearing capacity of the two specimens increases,and the slope of the rising section of the curve increases.When the axial compression ratio increases,the equivalent stiffness,displacement ductility coefficient and energy dissipation performance of the specimen decrease.(3)Compared with the cast-in-place integral specimen and the prefabricated specimen,the cast-in-place component is larger than the prefabricated component in the total hysteretic area;in the skeleton curve,the rising slope of the two is basically the same;however,in terms of degradation stiffness,ductility and energy dissipation performance,the cast-in-place integral components are better than the prefabricated components,indicating that the cast-in-place components are superior to the prefabricated components in terms of seismic performance. |
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